//-----------------------------------------------------------------------
// <copyright file="VectorExtensions.cs" company="Mapbox">
//     Copyright (c) 2016 Mapbox. All rights reserved.
// </copyright>
//-----------------------------------------------------------------------

namespace Mapbox.Unity.Utilities
{
	using Mapbox.Utils;
	using UnityEngine;

	public static class VectorExtensions
	{
		/// <summary>
		/// Vector2 convenience method to convert Vector2 to Vector3.
		/// </summary>
		/// <returns>Vector3 with a y value of zero.</returns>
		/// <param name="v">Vector2.</param>
		public static Vector3 ToVector3xz(this Vector2 v)
		{
			return new Vector3(v.x, 0, v.y);
		}

		/// <summary>
		/// Vector2d convenience method to convert Vector2d to Vector3.
		/// </summary>
		/// <returns>Vector3 with a y value of zero.</returns>
		/// <param name="v">Vector2d.</param>
		public static Vector3 ToVector3xz(this Vector2d v)
		{
			return new Vector3((float)v.x, 0, (float)v.y);
		}

		/// <summary>
		/// Vector3 convenience method to convert Vector3 to Vector2.
		/// </summary>
		/// <returns>The Vector2.</returns>
		/// <param name="v">Vector3.</param>
		public static Vector2 ToVector2xz(this Vector3 v)
		{
			return new Vector2(v.x, v.z);
		}

		/// <summary>
		/// Vector3 convenience method to convert Vector3 to Vector2d.
		/// </summary>
		/// <returns>The Vector2d.</returns>
		/// <param name="v">Vector3.</param>
		public static Vector2d ToVector2d(this Vector3 v)
		{
			return new Vector2d(v.x, v.z);
		}

		/// <summary>
		/// Transform extension method to move a Unity transform to a specific latitude/longitude.
		/// </summary>
		/// <param name="t">Transform.</param>
		/// <param name="lat">Latitude.</param>
		/// <param name="lng">Longitude.</param>
		/// <param name="refPoint">Reference point.</param>
		/// <param name="scale">Scale.</param>
		/// <example>
		/// Place a Unity transform at 10, 10, with a map center of (0, 0) and scale 1:
		/// <code>
		/// transform.MoveToGeocoordinate(10, 10, new Vector2d(0, 0), 1f);
		/// Debug.Log(transform.position);
		/// // (1113195.0, 0.0, 1118890.0)
		/// </code>
		/// </example>
		public static void MoveToGeocoordinate(this Transform t, double lat, double lng, Vector2d refPoint, float scale = 1)
		{
			t.position = Conversions.GeoToWorldPosition(lat, lng, refPoint, scale).ToVector3xz();
		}

		/// <summary>
		/// Transform extension method to move a Unity transform to a specific Vector2d.
		/// </summary>
		/// <param name="t">Transform.</param>
		/// <param name="latLon">Latitude Longitude.</param>
		/// <param name="refPoint">Reference point.</param>
		/// <param name="scale">Scale.</param>
		/// <example>
		/// Place a Unity transform at 10, 10, with a map center of (0, 0) and scale 1:
		/// <code>
		/// transform.MoveToGeocoordinate(new Vector2d(10, 10), new Vector2d(0, 0), 1f);
		/// Debug.Log(transform.position);
		/// // (1113195.0, 0.0, 1118890.0)
		/// </code>
		/// </example>
		public static void MoveToGeocoordinate(this Transform t, Vector2d latLon, Vector2d refPoint, float scale = 1)
		{
			t.MoveToGeocoordinate(latLon.x, latLon.y, refPoint, scale);
		}

		/// <summary>
		/// Vector2 extension method to convert from a latitude/longitude to a Unity Vector3.
		/// </summary>
		/// <returns>The Vector3 Unity position.</returns>
		/// <param name="latLon">Latitude Longitude.</param>
		/// <param name="refPoint">Reference point.</param>
		/// <param name="scale">Scale.</param>
		public static Vector3 AsUnityPosition(this Vector2 latLon, Vector2d refPoint, float scale = 1)
		{
			return Conversions.GeoToWorldPosition(latLon.x, latLon.y, refPoint, scale).ToVector3xz();
		}

		/// <summary>
		/// Transform extension method to return the transform's position as a Vector2d latitude/longitude.
		/// </summary>
		/// <returns>Vector2d that represents latitude/longitude.</returns>
		/// <param name="t">T.</param>
		/// <param name="refPoint">Reference point.</param>
		/// <param name="scale">Scale.</param>
		/// <example>
		/// Get the latitude/longitude of a transform at (1113195, 0, 1118890), map center (0, 0) and scale 1.
		/// <code>
		/// var latLng = transform.GetGeoPosition(new Vector2d(0, 0), 1);
		/// Debug.Log(latLng);
		/// // (10.00000, 10.00000)
		/// </code>
		/// </example>
		public static Vector2d GetGeoPosition(this Transform t, Vector2d refPoint, float scale = 1)
		{
			var pos = refPoint + (t.position / scale).ToVector2d();
			return Conversions.MetersToLatLon(pos);
		}

		public static Vector2d GetGeoPosition(this Vector3 position, Vector2d refPoint, float scale = 1)
		{
			var pos = refPoint + (position / scale).ToVector2d();
			return Conversions.MetersToLatLon(pos);
		}
	}
}
